In the past, International Publication Pamphlet No. WO 2008/117454 that generates a path/keyword matching automaton by replacing a tag of input extensible markup language (XML) data with a path ID for identifying a path in a path schema has been disclosed. Moreover, Japanese Laid-open Patent Publication No. 2003-323429 that generates a simple API for XML (SAX) event from input XML data and updates a path matching automaton in accordance with the generated SAX event has been disclosed.